Preheat the oven to 350°F (175°C), and coat a 4x8-inch loaf pan with butter or cooking spray.
To Make Brown Butter
Melt butter in shallow skillet or saute pan over medium heat, occasionally swirling the pan to ensure butter melts evenly.
A few minutes after it melts, the butter will begin to foam and the color will change from yellow to golden and then brown. When the butter has a nutty aroma, remove the pan from the heat and allow brown butter to cool.
Pumpkin Bread
Mash the ripe bananas in a large bowl with a fork by hand until smooth or in a mixing bowl with paddle. Add the pumpkin butter, browned butter, sugar, beaten egg, and vanilla.
Sift together the flour, baking soda and salt. Add to the bowl of wet ingredients and mix thoroughly to blend.
Pour batter into prepared loaf pan. Bake for 55 -60 minutes, or until a tester inserted into center comes out clean. If the bread is browning too quickly, tent the pan with aluminum foil.
Remove from oven and allow bread to cool in the pan for 10 minutes. Then run spatula between sides of pan and bread, tilt pan sideways and remove bread from loaf pan. Let cool on wire rack for at least 15-20 minutes before slicing.
Pumpkin Banana Muffins
Preheat the oven to 350°F (175°C). Lightly grease wells of 12-cup muffin pan with butter, or if desired, use non-stick baking spray to grease paper liners.
Make brown butter and bread batter as written above.
Pour batter into prepared muffin pan and bake in preheated oven for 18-22 minutes, or until toothpick inserted into center of a muffin comes out clean or with a few moist crumbs.
Remove pan from oven and allow muffins to cool in pan for 5 minutes, then transfer to wire cooling rack to finish cooling.